Method for controlling interference in femto cell deployments

ABSTRACT

A method and system provide a plurality of femto cells that are deployed within a macro cell of cellular network. The femto cells improve cellular service inside structures, such as residential and commercial structures. Femto base stations convert signals between an airlink-interface and core network to enable data communication between the mobile terminal and an access network to occur through the Internet and a public switched telephone network. The femto base stations are independent of each other and the macro cell. The method and system provide the femto base stations with interference awareness and mitigation techniques to minimize interference with the cellular network.

RELATED APPLICATION

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 12/919,878 filed Aug. 27, 2010 entitled “METHOD FORCONTROLLING INTERFERENCE IN FEMTO CELL DEPLOYMENTS”, Ser. No. 12/919,878is a Submission Under 35 U.S.C. §371 for U.S. National Stage PatentApplication of International Application Number: PCT/US2009/038094,filed Mar. 24, 2009 entitled “METHOD FOR CONTROLLING INTERFERENCE INFEMTO CELL DEPLOYMENTS”, which claims priority to U.S. ProvisionalApplication Ser. No. 61/039,176, filed Mar. 25, 2008, the disclosures ofwhich are incorporated by reference herein in their entirety.

BACKGROUND

Wireless carriers employ cellular towers to establish large cells toprovide wireless communications to cover large physical areas, such asmetropolitan or rural areas. The large cells or macro cells may coverareas of 1 km to 5 km in diameter. A cellular tower broadcasts wirelesssignals throughout the macro cell to large numbers of mobile handsets.

Various structures are typically located within the macro cell thatobstruct, reflect or otherwise interfere with the wireless signals. Forexample, users typically attempt to use mobile devices inside homes orcommercial establishments. These structures may be made from high lossmaterial, such as concrete or metal, which block wireless signals fromentering into the structures. The weak wireless signal reception withinthese structures degrades the quality of service, resulting inunreliable mobile communications. A system and method are needed toimprove cellular service inside structures.

SUMMARY

Some embodiments advantageously provide a method and system havinginterference awareness and provide mitigation techniques to femto basestations for minimizing interference with the cellular network. In somecases, various embodiments provide a method of reducing interferencebetween a femto cell and a macro cell in a wireless communicationnetwork. The method includes identifying a plurality of preselectedwireless signal carriers based on a predefined geographical area andmeasuring initial power levels for the wireless signal carriers providedin the predefined geographical area. One of the wireless signal carriersis selected based on predefined criteria associated with the measuredinitial power level. A transmission power level of a femto transmitteris adjusted based on a communication placed to a mobile terminal.

In accordance with another aspect, at least one embodiment provides asystem for reducing interference between a femto cell and a macro cellin a wireless communication network. The system includes a carrierselection module that identifies a plurality of preselected wirelesssignal carriers based on a predefined geographical area, measuresinitial power levels for the wireless signal carriers provided in thepredefined geographical area and selects one of the wireless signalcarriers based on predefined criteria associated with the measuredinitial power level. A fine tuning module is provided to adjust atransmission power level of a femto transmitter based on a communicationplaced to a mobile terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments, and the attendant advantages and features thereof,will be more readily understood by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a block diagram of an exemplary network architecture forwireless access networks constructed in accordance with one or moreembodiments;

FIG. 2 is a flow diagram of a method for adjusting the power level of afemto cell base station for a 1xRTT network in accordance with one ormore embodiments;

FIG. 3 is a flow diagram of a method for adjusting the power level of afemto cell base station for a 1xEV-DO network in accordance with one ormore embodiments; and

FIG. 4 is a flow diagram of a method for adjusting the power level of afemto cell based station for a Long Term Evolution network in accordancewith one or more embodiments.

DETAILED DESCRIPTION

Some embodiments provide femto base stations or home evolved Node-B toimprove cellular service inside structures, such as residential andcommercial structures, among other structures. The femto base stationsmay operate in the femto power range of about +15 dBm and may provide anoperation range of approximately 50 meters. The femto base stations arecoupled to the Internet and access mobile networks through thepublicly-switched telephone network. The femto base stations may useexisting broadband backhaul infrastructure from corresponding structuresto access the publicly-switched telephone network. For example, thefemto base stations may be coupled to a digital subscriber line (“DSL”)to access the publicly-switched telephone network.

Some embodiments can operate with existing cellular networks, such asCDMA2000 1xRTT, evolution-data optimized (“EV-DO”) and long-termevolution (“LTE”) networks, among other cellular networks. For example,the femto base stations or integrated low power consumer basetransceiver stations (“BTS”) and base station controllers (BSC) may formfemto cells to communicate with the mobile terminals using CDMAtechnology. The femto base stations may communicate over the Internetusing Session Initiation Protocol (“SIP”), among other signalingprotocols. The femto base stations convert signals between air interfaceand SIP to enable data communication between the mobile terminal and theInternet, thereby seamlessly providing service to wireless users.

At least one embodiments supports a plurality of femto cells that aredeployed within a macro cell. While the various femto base stations arecomponents of the overall communications network, each femto cell isseparate from the existing macro cell and any adjacent femto cells.During mobility, the system hands the mobile terminal communicationsession from a femto cell to the macro cell, or vice versa, or from afemto cell to another femto cell.

According to one embodiment, the macro cells and the femto cells employdifferent core networks, resulting in inter-technology handoffs orvertical handoffs (“VHO”) between the cells. VHO are performed when themobile terminals roam between different core networks, including movingout of a specified network or moving into a specified network. Thehandoff procedures may be initiated when signal strength measurementsoriginating in the active network, such as the cellular network or thefemto network, fall below pre-selected threshold parameters. The mobileterminal may detect the weak signal strength emanating from the “active”access network and may initiate a handoff to the “idle” access network,such as the femto base station network or the cellular network, having astronger signal strength, by reporting the weak signal to the activeaccess network.

Alternatively, the handoff procedures may be initiated to off-loadmobile terminal traffic from the cellular network to the femto basestation network. The femto base station is a personal and dedicated basestation for each corresponding structure. The femto base stations andthe cellular network supporting the macro cell independently supportnetwork traffic. Since the femto cells deployed within the macro cellare independently operated within the cellular network, the system doesnot provide integrated interference management between the macro cellsand the femto cells. If unregulated, the cellular network and the femtobase station networks produce mutual interference that may degradesystem quality of service. At least one embodiment provides the femtobase stations with interference awareness and mitigation techniques tominimize interference with the cellular network.

Referring now to the drawing figures in which like reference designatorsrefer to like elements, FIG. 1 illustrates an exemplary block diagram ofa system designated generally as “100” that enables mobile terminals 105a-105 n (referred to collectively herein as “mobile terminals 105”) tocommunicate with evolved Node-B (“eNB”) 110 using a first access network115 or second access networks 120 a-120 n (referred to collectivelyherein as “second access networks 120”) in accordance with theprinciples of one or more embodiments. The eNB 110 may include servers,transceivers for transmitting and receiving radio signals, and antennas.The eNB 110 may include two-way transceivers that broadcast data intothe surrounding environment and typically act as mediators between wiredand wireless networks.

The mobile terminals 105 may include a wide range of portable electronicdevices, including but not limited to mobile phones, personal dataassistants (“PDA”) and similar devices, which use the variouscommunication technologies such as advanced mobile phone system(“AMPS”), time division multiple access (“TDMA”), code division multipleaccess (“CDMA”), global system for mobile communications (“GSM”),general packet radio service (“GPRS”), 1x evolution-data optimized(abbreviated as “EV-DO” or “1xEV-DO”) and universal mobiletelecommunications system (“UMTS”). The mobile terminals 105 alsoinclude hardware and software suitable to support the control planefunctions needed to engage in wireless communication with eNB 110 andfemto base stations 125. Such hardware may include a receiver,transmitter, central processing unit, storage in the form of volatileand nonvolatile memory, and input/output devices, among other hardware.

The first access network 115 may include a CDMA 1xRTT network, an EV-DOnetwork or a LTE network, among other access networks. The second accessnetworks 120 may include femto base stations 125 a-125 n (referred tocollectively herein as “femto base stations 125”) that are coupled to apublic switched telephone (PST) network 130 via a local network 132,such as the Internet, and an Internet Service Provider (ISP) router 134.The PST network 130 may be coupled to a cellular base transceiverstation (BTS) 140, which is coupled to the eNB 110. The system 100coordinates handing off the mobile terminals 105 between the firstaccess network 115 and the second access networks 120.

The cellular network operates in a conventional manner, controlling thefirst access network or the macro cell 115 to efficiently cooperate withadjacent macro cells. For example, the cellular network may adjustcharacteristics, such as transmission power or noise level, among othercharacteristics.

Some embodiments are directed to managing the second access networks120. The second access networks 120 may be provided to operate insidecorresponding structures 145 a-145 n (referred to collectively herein as“structures 145”). The structures 145 may include residential orcommercial structures, among other structures. The structures 145 may bemade from high loss materials, such as concrete, brick or metal, amongother high loss materials that block wireless signals from penetratingthe structures 145. As a result, any communication signals that arebroadcast from the eNB 110 may not be received within the structures145. Similarly, any communication signals that are broadcast from thefemto base stations 125 may not be transmitted outside the structures145. Likewise, any communication signals that are broadcast from themobile terminals 105 while located inside the structures 145 may not bereceived at the eNB 110. Any communication signals that are broadcastfrom the mobile terminals 105 while located outside the structures 145may not be received at the femto base stations 125.

The second access networks 120 are localized networks that areestablished by users to provide communication signals insidecorresponding structures 145. A decision to initiate hand off of themobile terminal 105 between the first access network 115 and the secondaccess networks 120 may occur when the “active” access networkdetermines that the relevant mobile terminal 105 will be better servedby the “idle” access network. Criteria for initiating a hand off betweenthe first access network 115 and the second access networks 120 includepreventing the mobile terminals 105 from “falling off” the active accessnetwork or alleviating load conditions at the active access network,among other criteria. In this regard, the femto cells 120 may beconfigured to concurrently support various terminal devices 105. Anyterminal devices 105 that are supported by the second access network,through femto base station 125, are routed to the cellular basetransceiver station 140 via network 132. Thus, these mobile devices 105do not use resources from the first access network 115. However,deploying a large number of active femto cells 120 within a macro cell115 may increase a probability of overloading cellular networkresources, such as overloading the macro cell uplink anddegrading/increasing interference levels to the mobile devices 105 onthe down link, among other forms of overloading cellular networkresources. Overloading cellular network resources limit macro cellcoverage area and capacity.

The femto base stations 125 may include a central processing unit(“CPU”), transmitter, receiver, I/O devices and storage, such asvolatile and nonvolatile memory, to implement the functions describedherein. The femto base stations 125 may communicate with the mobileterminals 105 over a radio interface.

The femto base station 125 may be of modular construction to facilitateadding, deleting, updating and/or amending modules therein and/orfeatures within modules. Modules may include a mobility managementmodule 150, a radio access network (“RAN”) module 152, a carrierselection module 154, a power control module 156, and a fine tuningmodule 158, among other modules. The mobility management module 150manages the hand off of the mobile terminals 105 between the macro cell115 and the femto cell 120, performs authentication of mobile terminals105 and provides supplementary services. The RAN module 152 performs anair-interface to SIP translation and converts between the first accessnetwork protocol and the second access network protocol, and vise versa.For example, the RAN module 152 may provide conversion between CDMA/3GPPcommunications over the air and SIP communications via the broadbandbackhaul.

During an initialization period, the carrier selection module 154 mayaccess a memory structure to obtain a list of available wirelesscarriers and corresponding frequency ranges. For example, the carrierselection module 154 may access a database to obtain a list of wirelesscarriers that are available for a predefined geographical area. Thegeographical area information may be obtained manually by requestinginformation from the user or automatically through a global positioningsystem, or other techniques. The carrier selection module 154 mayactivate a CDMA forward link receiver to measure the initial power level(I_(o)) or the Received Signal Strength Indication (“RSSI”) within aselected bandwidth to identify the strength of the incoming signal. Thecarrier selection module 154 may sort the (I_(o)) or RSSI informationaccording to predefined criteria. The predefined criteria may include,for example, power level or amount of loading, among other predefinedcriteria. The carrier selection module 154 may select a wireless carrierby selecting a frequency that is unoccupied, free of interference, orcontains a minimum amount of power. Systems that generate high powerreadings typically include high traffic volume.

Alternatively, the carrier selection module 154 may include an operationmanager that eliminates any unused CDMA carriers from the list ofavailable carriers. Any unused CDMA carriers may be preserved for futureexpansion opportunities.

After selecting a wireless carrier, the power control module 156 mayperform a coarse power adjustment of a transmitter that is associatedwith the femto base station 125. The power control module 156 may beconfigured to define a boundary for the femto cells 120 that remainswithin the corresponding structure 145. Otherwise, if the femto cell 120is not managed to operate within the corresponding structure 145, thenthe transmission power from the femto base station 125 may negativelyimpact performance of the macro cell uplink or downlink One formula foradjusting the power level may include: (Measured Macro Cell InitialPower Level)−(Expected Femto Path Loss)=Femto Initial Transmission. Themeasured macro cell initial power level is a femto measured initialpower level for the selected wireless signal carrier. The expected femtopath loss is a pre-defined variable based on a femto location or aprofile for deployment. The expected femto path loss may be obtained byrequesting the information from users during an initial set-upprocedure.

During an initial set-up, the user may be prompted to enter adescription of the intended environment for the femto base station 125.The description may include a type of structure, such as an apartment, asingle family home, a warehouse, and an approximate square footmeasurement. The apartment may be defined to include a cell radius of 10m, with an expected path loss of 39 dB (for lm at 1900 Hz) and +30 dBfor every 10×distance.

In addition to interfering with the macro cell, a femto cell also mayinterfere with adjacent femto cells. For example, the femto cell 120 amay interfere with adjacent femto cell 120 n. At least some embodimentsare directed to minimizing interference between the macro cell andassociated femto cells that are deployed on the same radio frequency(“RF”) carriers. To minimize interference between adjacent femto cells,the carrier selection module 154 may select a wireless carrier for afemto cell that is initialized second in time that is different from afemto cell that is initialized first in time. The carrier selectionmodule 154 may activate a CDMA forward link receiver to measure theinitial power level (I_(s)) or the Received Signal Strength Indication(“RSSI”) within a selected bandwidth to identify the strength of theincoming signal. The carrier selection module 154 may sort the I_(o) orRSSI information according to predefined criteria. The predefinedcriteria may include, for example, power level or amount of loading,among other predefined criteria.

After establishing the initial power transmission level, the fine tuningmodule 158 may initiate a call to the target mobile terminal 105. Thefine tuning module 158 sends a message to the target mobile terminal105, such as an IS-2000/IS-856 message, requesting periodic pilotstrength measurements. The fine tuning module 158 compares the receivedpilot strength measurement to predefined threshold. If the pilotstrength measurement exceeds the predefined threshold value, then thetransmission power is reduced and the reception attenuation is increasedby a preselected amount, such as 1 dB or other amount. The fine tuningmodule 158 repeats the process of decreasing the transmission poweruntil the pilot strength measurement falls below the predefinedthreshold value.

An exemplary power adjustment algorithm for the femto base station 125operating in the 1xRTT network is discussed with reference to FIG. 2. Instep S202, at initialization, an operation manager provides a list ofvalid wireless carriers that are authorized for a preselected region.The initial power level (I_(o)) or the Received Signal StrengthIndication (RSSI) is measured within a selected bandwidth to identifythe strength of the incoming signal (step S204). In step S206, the RSSIis sorted from lowest to highest. A wireless carrier is selected fromthe highest sorted RSSI (step S208). In step 5210, a coarse adjustmentof the transmission power level is performed. The network initiates acall to the mobile terminal (step S212). A periodic pilot strengthmeasurement is requested (step S214). In step S216, a determination ismade of whether any macro cell private network (“PN”) is reported. Theprocess is terminated when the macro cell PN is reported (step S218). Ifa PN is not reported then a threshold value comparison is performed(step S220). If a ratio of a received pilot energy value to the totalreceived energy (E_(c)/I_(o)) value is below a threshold value, then theprocess is terminated (step S222). Otherwise, if the E_(c)/I_(o) ratiois above a predefined threshold value, then the transmission power isreduced (step S224). Steps S214-S224 are repeated until the macro cellPN is reported and terminated in step S218 or the E_(c)/I_(o) ratio isbelow a threshold value and the process is terminated in step S222.

The system 100 permits establishing adjustable parameters for the 1xRTTnetwork to optimize the power adjustment algorithm of the femto basestation 125. The adjustable parameters may include power levels (e.g.,E_(c)/I_(o) threshold), handoff settings (e.g., T-Add, T-Drop, T-Compthresholds), periodicity of pilot strength measurement message (PPSMM),search windows, filtering constant (e.g., E_(c)/I_(o) measurements andthe femto power control step, among other parameters.

An exemplary power adjustment algorithm for the femto base station 125operating in the 1xEV-DO network is discussed with reference to FIG. 3.At initialization, an operation manager provides a list of validwireless carriers that are authorized for a preselected region (stepS302). In step S304, the initial power level (Io) or the Received SignalStrength Indication (“RSSI”) is measured within a selected bandwidth toidentify the strength of the incoming signal. The RSSI is sorted fromlowest to highest (step S306). A wireless carrier is selected from thehighest sorted RSSI (step S308). A coarse adjustment of the transmissionpower level is performed (step S310). In step S312, the networkinitiates a call to the mobile terminal. A data rate control (DRC)average is evaluated (step S314). In step S316, a determination is madeof whether the DRC is below a threshold. In step S318, the process isterminated when the DRC is below a threshold. If the DRC is not below athreshold, then the transmission power is reduced (step S320). StepsS314-S320 are repeated until the DRC falls below the threshold and theprocess is terminated in step S318.

The system 100 permits establishing adjustable parameters for the1xEV-DO network to optimize the power adjustment algorithm of the femtobase station 125. The adjustable parameters may include a DRC thresholdand filtering constants for the DRC measurements, among otherparameters.

An exemplary power adjustment algorithm for the femto base station 125operating in the 3GPP (LTE) network is discussed with reference to FIG.4. At initialization, an operation manager provides a list of validwireless carriers that are authorized for a preselected region (stepS402). In step S404, the initial power level (Io) or the Received SignalStrength Indication (“RSSI”) is measured within a selected bandwidth toidentify the strength of the incoming signal. The RSSI is sorted fromlowest to highest (step S406). A wireless carrier is selected from thehighest sorted RSSI (step S408). A coarse adjustment of the transmissionpower level is performed (step S410). In step 5412, the networkinitiates a call to the mobile terminal. A signal quality indicator(CQI) average is evaluated (step S414). In step S416, a determination ismade of whether the CQI is below a threshold. In step S418, the processis terminated when the CQI is below a threshold. If the CQI is not belowa threshold, then the transmission power is reduced (step S420). StepsS414-S420 are repeated until the CQI falls below the threshold and theprocess is terminated in step S418.

The system 100 permits establishing adjustable parameters for the 3GPP(“LTE”) network to optimize the power adjustment algorithm of the femtobase station 125. The adjustable parameters may include a CQI thresholdand filtering constants for the CQI measurements, among otherparameters.

It should be appreciated that, while described with reference to the1xRTT and the EV-DO network, the principles discussed may be adapted byone of skill in the art to migrate between any networks, including othernetworks, such as LTE networks, UMTS networks, WiMAX (802.16) networks,other CDMA2000 networks and any other networks known in the art or laterdeveloped.

Various embodiments can be realized in hardware, software, or acombination of hardware and software. Any kind of computing system, orother apparatus adapted for carrying out the methods described herein,is suited to perform the functions described herein.

A typical combination of hardware and software could be a specializedcomputer system having one or more processing elements and a computerprogram stored on a storage medium that, when loaded and executed,controls the computer system such that it carries out the methodsdescribed herein. Some embodiments can also be embedded in a computerprogram product, which comprises all the features enabling theimplementation of the methods described herein, and which, when loadedin a computing system is able to carry out these methods. Storage mediumrefers to any volatile or non-volatile storage device.

Computer program or application in the present context means anyexpression, in any language, code or notation, of a set of instructionsintended to cause a system having an information processing capabilityto perform a particular function either directly or after either or bothof the following a) conversion to another language, code or notation; b)reproduction in a different material form.

In addition, unless mention was made above to the contrary, it should benoted that all of the accompanying drawings are not to scale.Significantly, one or more embodiments can vary in form withoutdeparting from the spirit or essential attributes thereof, andaccordingly, reference should be had to the following claims, ratherthan to the foregoing specification, as indicating the scope of theclaimed subject matter. It will be appreciated by persons skilled in theart that the present invention is not limited to what has beenparticularly shown and described herein above. In addition, unlessmention was made above to the contrary, it should be noted that all ofthe accompanying drawings are not to scale. A variety of modificationsand variations are possible in light of the above teachings withoutdeparting from the scope and spirit of the claimed subject matter.

What is claimed:
 1. One or more computer-readable storage memoriesembodying processor-executable instructions which, responsive toexecution by at least one processor, are configured to: identify, usinga femto cell in a wireless communication network, a plurality ofpreselected wireless signal carriers based on a predefined geographicalarea; measure, using the femto cell, initial power levels for thewireless signal carriers provided in the predefined geographical area;select, using the femto cell, one of the wireless signal carriers basedon predefined criteria associated with the measured initial power level;and adjust, using the femto cell, a transmission power level of a femtotransmitter associated with the femto cell based on a communicationplaced to a mobile terminal.
 2. The one or more computer-readablestorage memories according to claim 1, wherein the processor-executableinstructions to identify the plurality of preselected wireless signalcarriers are further configured to identify the plurality of preselectedwireless signal carriers based, at least in part, on the location of thefemto cell.
 3. The one or more computer-readable storage memoriesaccording to claim 1, wherein the processor-executable instructions tomeasure the initial power levels for each wireless signal carrier of theplurality of preselected wireless signal carriers are further configuredto measure the receive signal strength indicator of each wireless signalcarrier of the plurality of preselected wireless signal carriers.
 4. Theone or more computer-readable storage memories according to claim 1, theprocessor-executable instructions further configured to sort themeasured initial power levels for each wireless signal carrier of theplurality of preselected wireless signal carriers.
 5. The one or morecomputer-readable storage memories according to claim 1, wherein thepredefined criteria associated with selecting one of said plurality ofpreselected wireless signal carriers includes at least one of supportinga lowest amount of mobile terminal traffic and providing a highestinitial power level.
 6. The one or more computer-readable storagememories according to claim 1, wherein the processor-executableinstructions to adjust the transmission power level of the femtotransmitter are further configured to adjust the transmission powerlevel of the femto transmitter based on: (Measured Macro Cell InitialPower Level)- (Expected Femto Path Loss), wherein the measured macrocell initial power level is a femto measured initial power level for theselected wireless signal carrier and the expected femto path loss ispre-defined variable based on a femto location or a profile fordeployment.
 7. The one or more computer-readable storage memoriesaccording to claim 1, the processor-executable instructions furtherconfigured to: request a periodic pilot strength measurement; and reducethe transmission power if the pilot strength measurement is above athreshold value.
 8. The one or more computer-readable storage memoriesaccording to claim 1, the processor-executable instructions furtherconfigured to: request a periodic pilot strength measurement; andmaintain the transmission power if the pilot strength measurement isbelow a threshold value.
 9. The one or more computer-readable storagememories according to claim 1, the processor-executable instructionsfurther configured to: obtain at least one of an average data ratecontrol value and an average signal quality indicator value; and reducethe transmission power if at least one of the average data rate controlvalue and the average signal quality indicator value is above athreshold value.
 10. The one or more computer-readable storage memoriesaccording to claim 1, the processor-executable instructions furtherconfigured to: obtain at least one of an average data rate control valueand an average signal quality indicator value; and maintain thetransmission power if at least one of the average data rate controlvalue and the average signal quality indicator value is below athreshold value.
 11. One or more computer-readable storage memoriesembodying processor-executable instructions which, responsive toexecution by at least one processor, are configured to enable a deviceto: identify, using a femto cell in a wireless communication network, aplurality of preselected wireless signal carriers based on a predefinedgeographical area; measure, using the femto cell, initial power levelsfor the wireless signal carriers provided in the predefined geographicalarea; select, using the femto cell, one of the wireless signal carriersbased on predefined criteria associated with the measured initial powerlevel; establish, using the femto cell, a transmission power level of afemto transmitter associated with the femto cell; request, using thefemto cell, a pilot strength measurement from an associated targetmobile device; receive, using the femto cell, said requested pilotstrength measurements from the target mobile device; responsive todetermining that said received pilot strength measurement exceeds apredefined threshold, repeat, using the femto cell, said requesting andreceiving pilot strength measurements from the target mobile until areceived pilot strength measurement falls below a predefined thresholdvalue; and responsive to determining that said received pilot strengthmeasurement falls below the predefined threshold, maintain atransmission power associated with said received pilot strengthmeasurement below the predefined threshold.
 12. The one or morecomputer-readable storage memories of claim 11, wherein theprocessor-executable instructions are configured to, responsive todetermining that said received pilot strength measurement exceeds apredefined threshold, enable the device to: reduce the transmissionpower level associated with the device; and increase a receptionattenuation value associated with the device.
 13. The one or morecomputer-readable storage memories of claim 11, wherein theprocessor-executable instructions are configured to enable the device toperform a power adjustment algorithm based, at least in part, onadjustable parameters associated with a Code Division Multiple Access(CDMA) 200 1xRTT network.
 14. The one or more computer-readable storagememories of claim 13, wherein the adjustable parameters include at leastone of: at least one hand-off setting; a filtering constant measurement;or a periodicity of pilot strength measurement message.
 15. The one ormore computer-readable storage memories of claim 11, wherein theprocessor-executable instructions are configured to enable the device toperform a power adjustment algorithm based, at least in part, onadjustable parameters associated with a 1x Evolution-Data Optimized(1xEV-DO) network.
 16. The one or more computer-readable storagememories of claim 15, wherein the adjustable parameters include at leastone of: a data rate control (DRC) threshold; or a filtering constantmeasurement associated with DRC measurements; or a periodicity of pilotstrength measurement message.
 17. The one or more computer-readablestorage memories of claim 11, wherein the processor-executableinstructions are configured to enable the device to perform a poweradjustment algorithm based, at least in part, on adjustable parametersassociated with a 3GPP long-term evolution (LTE) network.
 18. The one ormore computer-readable storage memories of claim 15, wherein theadjustable parameters include at least one of: a signal qualityindicator (CQI) threshold; or a filtering constant measurementassociated with CQI measurements.
 19. A computer implemented methodcomprising: identifying, using a femto cell in a wireless communicationnetwork, a plurality of preselected wireless signal carriers based on apredefined geographical area; measuring, using the femto cell, initialpower levels for the wireless signal carriers provided in the predefinedgeographical area; selecting, using the femto cell, one of the wirelesssignal carriers based on predefined criteria associated with themeasured initial power level; establishing, using the femto cell, atransmission power level of a femto transmitter associated with thefemto cell; requesting, using the femto cell, a pilot strengthmeasurement from an associated target mobile device; receiving, usingthe femto cell, said requested pilot strength measurements from thetarget mobile device; responsive to determining that said received pilotstrength measurement exceeds a predefined threshold, repeating, usingthe femto cell, said requesting and receiving pilot strengthmeasurements from the target mobile until a received pilot strengthmeasurement falls below a predefined threshold value; and responsive todetermining that said received pilot strength measurement falls belowthe predefined threshold, maintaining a transmission power associatedwith said received pilot strength measurement below the predefinedthreshold.
 20. The computer-implemented method of claim 19 furthercomprising, responsive to determining that said received pilot strengthmeasurement exceeds a predefined threshold: reducing the transmissionpower level associated with the device; and increasing a receptionattenuation value associated with the device.